Clock



FIG. 1 is a front elevational view of a clock showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a right side elevational view thereof, the left side being the same in appearance as the right side;

FIG. 4 is a top plan view thereof, the bottom being the same in appearance as the top;

FIG. 5 is a bottom and right front perspective view thereof; and

FIG. 6 is a bottom and left rear perspective view thereof. 

The ornamental design for a clock, as shown and described. 